package com.pocketsweet.ui.uilib;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;

import com.pocketsweet.R;

/**
 * @describe 使用了第三方的 SwitchButton，添加了相关属性的注释，更容易看懂
 * @author https://github.com/Issacw0ng/SwitchButton
 *
 */
/**
 * @describe 使用了第三方的 SwitchButton，添加了相关属性的注释，更容易看懂
 * @author https://github.com/Issacw0ng/SwitchButton
 * 
 */
public class CheckSwitchButton extends View implements OnTouchListener {
	private boolean nowChoose = false;// 记录当前按钮是否打开，true为打开，false为关闭
	private boolean onSlip = false;// 记录用户是否在滑动
	private float downX, nowX; // 按下时的x，当前的x
	private Rect btn_on, btn_off;// 打开和关闭状态下，游标的Rect

	private boolean isChgLsnOn = false;// 是否设置监听
	private OnChangedListener changedLis;

	private Bitmap bg_on, bg_off, slip_btn;

	public CheckSwitchButton(Context context, AttributeSet attrs) {
		super(context, attrs);
		init();
	}

	public CheckSwitchButton(Context context) {
		super(context);
		init();
	}

	public boolean isNowChoose() {
		return nowChoose;
	}

	public void setNowChoose(boolean nowChoose) {
		// changedLis.OnChanged(nowChoose);

		this.nowChoose = nowChoose;
	}

	private void init() {
		// 载入图片资源
		bg_on = BitmapFactory.decodeResource(getResources(),
				R.drawable.sild_bg_on);
		bg_off = BitmapFactory.decodeResource(getResources(),
				R.drawable.sild_bg_off);
		slip_btn = BitmapFactory.decodeResource(getResources(),
				R.drawable.sild_btn);
		// 获得需要的Rect数据
		btn_on = new Rect(0, 0, slip_btn.getWidth(), slip_btn.getHeight());
		btn_off = new Rect(bg_off.getWidth() - slip_btn.getWidth(), 0,
				bg_off.getWidth(), slip_btn.getHeight());
		setOnTouchListener(this);
	}

	@Override
	protected void onDraw(Canvas canvas) {
		// TODO Auto-generated method stub
		super.onDraw(canvas);

		Matrix matrix = new Matrix();
		Paint paint = new Paint();
		float x;

		{
			if (nowX < (bg_on.getWidth() / 2) && !isNowChoose()) // 滑动到前半段与后半段的背景不同,在此做判断
				canvas.drawBitmap(bg_off, matrix, paint);// 画出关闭时的背景
			else
				canvas.drawBitmap(bg_on, matrix, paint);// 画出打开时的背景

			if (onSlip) {// 是否是在滑动状态,
				if (nowX >= bg_on.getWidth())// 是否划出指定范围,不能让游标跑到外头,必须做这个判断
					x = bg_on.getWidth() - slip_btn.getWidth() / 2;// 减去游标1/2的长度
				else
					x = nowX - slip_btn.getWidth() / 2;
			} else {
				if (nowChoose)// 根据现在的开关状态设置画游标的位置
					x = btn_off.left;
				else
					x = btn_on.left;
			}

			if (x < 0) // 对游标位置进行异常判断..
				x = 0;
			else if (x > bg_on.getWidth() - slip_btn.getWidth())
				x = bg_on.getWidth() - slip_btn.getWidth();

			canvas.drawBitmap(slip_btn, x, 0, paint);// 画出游标.
		}
	}

	@Override
	public boolean onTouch(View v, MotionEvent event) {

		switch (event.getAction()) {// 根据动作来执行代码

		case MotionEvent.ACTION_MOVE:// 滑动
			nowX = event.getX();
			break;
		case MotionEvent.ACTION_DOWN:// 按下
			if (event.getX() > bg_on.getWidth()
					|| event.getY() > bg_on.getHeight())
				return false;
			onSlip = true;
			downX = event.getX();
			nowX = downX;
			break;
		case MotionEvent.ACTION_UP:// 松开
			onSlip = false;
			boolean lastChoose = nowChoose;
			if (event.getX() >= (bg_on.getWidth() / 2))
				nowChoose = true;
			else
				nowChoose = false;
			if (isChgLsnOn && (lastChoose != nowChoose))// 如果设置了监听器,就调用其方法.
				changedLis.OnChanged(nowChoose);
			break;
		default:
			break;
		}
		invalidate();
		return true;
	}

	public void SetOnChangedListener(OnChangedListener l) {// 设置监听器,当状态修改的时候
		isChgLsnOn = true;
		changedLis = l;
	}

	public interface OnChangedListener {
		abstract void OnChanged(boolean checkState);
	}
}
